SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f87286d398fc37cc9eabd26ee172e7419746525da033bcd9f0ffd0107bd7a227' 
  AND token = 'o/MN94J0domQOhoPmdCe7fl55xSBQlMy5Tk8y7REwyQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}